Oil-soluble copper-nicotine compounds and process of preparing same



Patented Jan. 14, 1947 OIL-SOLUBLE COPPER-NICOTINE COM- POUNDS ANDPROCESS OF PREPAR- ING SAME Claude It. Smith, Philadelphia, Pa.,assignor to United States of America, as represented Secretary ofAgriculture by the No Drawing. Application February 15, 1944, Serial No.522,528

(Granted under the act of March 3. 1883, as

12 Claims.

amended April 30, 1928: 370 0. G. 757) 1 This application is made underthe act of March 3, 1883, as amended by the act of'April 30, 1928, andthe invention herein described, if patented, may be manufactured andused-by or for the Government of the United States of Americaforgovernmental purposes without the payment to me of any royaltythereon.

Ellis-invention relates to copper-nicotine com- ---=pounds,--and hasamong its objects the producment, and so forth, but the toxicity of theoil to the ova, larvae, and adults of many insects, when in theconcentrations tolerated by the host, is often insufficient foreffective insect control.

Attempts have frequently been made to increase the toxicity of the oilby dissolving other toxic ingredients therein. Compounds of nicotinehave been recognized as desirable for this purpose, but heretoforesatisfactory nicotine compounds have not been available. The knowncompounds although soluble in the oil are also soluble in water,rendering them unsuitable.

For example nicotine, if free from water, and a number of its derivativecompounds, such as its simple salts with some members of the fattyacids, naphthenic acid, and so forth, can be dissolved in a dryhydrocarbon oil, but when these 1 solutions are brought into contactwith water, the nicotine or its salts largely pass from the oil intosolution in the water.

I have found that certain members of the soapforming acids can be formedinto their normal cupric salts and then reacted with nicotine by theacid, both of which are insoluble in oil in the presence of water,whereas the normal cupric mixing the nicotine and normal cupric saltstogether to form copper-nicotine compounds soluble in hydrocarbon oil,but not soluble in water, thus resulting in nicotine compoundaeminentlysuitable for the purposes mentioned above.

By soap-forming acids is meant those acids as herein used that formsodium or potassium salts with theproperty of binding water into agelatinous mass, commonly referred to as soap." For example,the'saturated aliphatic monocarboxylic acids having from 6 to 14 carbonatoms, inclusive are such soap-forming acids. The saturated aliphaticmonoca'rboxylic acids below hexanoic are not soap-forming acids, andtheir inormal cupric salts, when treated with nicotine,

the precipitated cupric salts of the soap-forming acids used in thisinvention react with nicotine without decomposition to formcopper-nicotine compounds whichare soluble in oil and not in water. Itis to be understood that use of an excess of nicotine in producing thecopper-nicotine compounds from the normal cupric salts may causedecomposition, even with the cupric salts of the soap-forming acids;hence, the amount of nicotine used should generally be limited to theproportion of not sub stantially more than one molecule of nicotine foreach molecule of the cupric salt, although nicotine in an amount up to 1molecules may be used.

Other soap-forming acids suitable for use in forming the copper-nicotinecompound of this invention include unsaturated aliphatic monocarboxylicacids having from 6 to 18 carbon atoms,

form cupric hydroxide and the nicotine salt of inclusive, such as9-hendecenolc acid. 9-octadecenoic acid (oleic), 9,12,0ctadecadienoicacid (linoleic) ,.and so forth, whose normal cupric salts are soluble inoil, and abietic acid derived from pine rosin,

Chemically pure soap-forming acids are very expensive, and. it is notnecessary for the purposes of this invention to employ them. Mixtures ofsuch acids, such as the mixed acids from cocoanut oil, or variousfractions derived from mixed acids, may be used. Commercial fatty acidsmay also be used. However, hexadecanoic (palmitic) and octadecanoic(stearic) acids, if present in substantial amounts in the commercialfatty acids, must be removed at some stage in the preparation of thecopper-nicotine compounds, but if their proportions are small, as insome commercial mixed cocoanut oil fatty acids, their removal is notrequired, probably because the solvent action of the oil-solublecopper-nicotine compounds prevents precipitation of the compounds of thepalmitic and stearic acids. Use of commercial oleic acid usuallyrequires a preliminary separation 'of the oil-soluble fraction fromsalts associated with the water phase.

The "process of preparing the new oil-soluble, V water-insolublecopper-nicotine compounds in- 1 volves two essential steps: first, thepreparation of the normal cupric salt of the soap-forming acid, andsecond, the addition of nicotine to the normal cupric salt to form themononicotine compound of copper.

The normal cupric salt of the soap-forming acid can made by the addition01' a water solution of a s luble cupric salt, such as cupric acetate orcopper sulfate, to a carefully neutralized solution of the sodium saltof the acid. With individual acids or mixtures of acids, the alkaliequivalent determines the correct amount of copper required to form thenormal cupric salt.

The precipitated normal cupric salt or salts may be converteddirectly tothe copper-nicotine compound or compounds by the addition of 1 to 1moles of nicotine per mole of cupric salt dissolved in water andvigorously shaken to effect intimate contact.

The copper-nicotine compound may be extrected from the reaction massdirectly by the hydrocarbon oil in which the copper-nicotine compound isto be used, or if a concentrated form of the compound is desired, it maybe extracted by some volatile solvent such as petroleum ether or ethylether, following which the solvent may be removed by evaporation.

The normal cupric salt of the soap-forming acid often can beconveniently prepared directly in the hydrocarbon base in which it isdesired to have the copper-nicotine compound dissolved, by firstdissolving the soap-forming acid in the oil and thoroughly mixing thesolution thus formed with an aqueous solution of the cupric salt of aweak acid such as cupric acetate. Different soap-forming acids vary inthe completeness of the change to the cupric salt, partly because of thereverse effect of the liberated acetic acid. However, complete changecan be assured by careful neutralization of the acetic acid betweenintervals of shaking or by discarding the cupric acetate water layerwhich forms on standing and using additional quantities of the cupricacetate solution. The copper-nicotine compound dissolved in thehydrocarbonoil is then formed by adding nicotine. Abietic acid when usedas the soap-formin acid in the manner mentioned in the first paragraphabove does not dissolve readily in hydrocarbon oils, so that thepreparation of the normal cupric salt of this acid is preferablv carried4 7 Example One-tenth molar weight of hexanoic acid (11.6 grams) wasdissolved in 200 ml. of a refinedkerosene oil. One-twentieth molarweight of cupric acetate dihydrate was dissolved in sumcient water andshaken vigorously with the oil solution to form the normal cupric saltin solution in the oil. After standing, the water layer was withdrawnand then two grams of the cupric acetate in water solution was shakenwith the voil layer to complete the change of the acid to the normalcupric salt. One-twentieth molar weight of nicotine (8.1 grams) wasadded directly to the solution of oil and the cupric salt to form thecopper-nicotine compound, with a resulting color change from blue tobright green.

Example II pared in the oil phase as in Example 1, except I that severalsuccessive portions of cupric acetate solution were required to completethe change to the normal salt. The normal cupric salt was formed partlyin solution in the oil but mostly in a suspension. The addition ofone-twentieth molar out in an ether solution. According to this pro- 7cedure, the acid is combined with the nicotine and ethereal solution andthe ether later is removed by evaporation. I

Most of the normal cupric salts of the saturated aliphaticmonocarboxylic acids are usually only slightly solub e in petroleum oil.Cupric hexanoate is an exception, being qu te soluble. The normal cupricsalts of the unsaturated fatty acids are generally soluble in the oil,but the normal cupric abietate is only slightly soluble. However, theaddition-of one molecule of nicotine to each molecule of the cupric saltresults in formation of the copper-nicotine compounds from the insolublecupric salts which are soluble in oil without affecting the solubilityof those compounds already dissolved.

The different copper nicotine compounds derived? from differentsoap-forming acids do not vary substantially in solubility in thepetroleum oils, even thoughoils difl'eringin range of boiling point-andviscosity be used; but the more viscous.

oils-require a longer time to complete the solution.

The; examples given below serve to'illustrate the essential steps in theprocess of preparing coppen nicotine compounds dissolved in a desiredoili base. Commercial methods may vary with the; acid or acids to beused, and differ in detail from: the convenient procedures indicated.

' and thenormal cupric salt formed as in Example.

weight of nicotine produced a color change similar to that of Example 1,resulting from chemical combination of the nicotine and cupric saltfollowed by solution of the copper-nicotine compound in the oil. ExampleIII One-tenth molar weight. of octanoic acid (14.4 grams was dissolvedin 200 ml. of the refined kerosene oil and treated as in Example 11. Thecupric salt was formed in suspension in the oil but combined anddissolved on the addition of the nicotine as in Example 11.

Example IV One-tenth molar weight of decanoic acid (17.2

grams) was dissolved in refined kerosene oil and treated as in ExampleII. The normal cupric salt was formed in suspension in the oil butcombined and dissolved on addition of the nicotine and gave thecharacteristic bright green solution.

Example V- Example VI One-tenth molar weight of tetradecanoic acid (22.8grams) was dissolved in 200 ml. of refined kerosene oil. The cupric saltwas formed as in Example II, with the resulting formation of a viscousmass as'in Example V. The addition of nicotine produced completesolution only on.

warming. In the cold, some insoluble material was formed, probablyindicating the limit of.

solubility had been passed.

' Example VII One-tenth molar weight of 9-hendecenoic acid was dissolvedin 200 ml. of refined kerosene oil II. The normal cupricv salt remaineddissolved in the oil and was combined and. changed to the characteristicbright green color on addition of nicotine. The substitution of a mediumgrade summer oil for the kerosene in a parallel experiment gave similarresulting products in all steps of the procedure,

Example VIII One-tenth molar weight (30.2 grams) of abietic acid(actuallya good grade cf'pine rosin) was dissolved in 100 ml. of ethylether. The normal cupric salt was prepared by shaking with cupricacetate solution, as in Example 11. Onetwentieth molar weight ofnicotine (8.1 grams) and 200 ml. of kerosene oil was added to theethereal solution. The ether was removed by evaporation. Some impuritiesseparated from the oil on standing several days, permitting decantationof the clear, green copper-nicotine compound in oil solution.

Example IX ical having from 5 to l! carbon atoms, inclusive,

or the abietyl radical, and wherein ClllHl4N2 represents a molecule ofnicotine.

Other methods of preparing normal. cupric salts of the desired acid oracids and also variation in the order of adding the petroleum oil andnicotine are possible without departing from the essential stepsrequired for the formation of the selected mononicotine compounds ofcopper.

Having thus described the invention, what is claimed is: y

1. A process for the preparation or oil-soluble copper-nicotinecompounds comprising reacting nicotine with a normal cupric sale of asoap- One-tenth average molar weight of the mixed cocoanut oil. fattyacids (20.0 grams) was dissolved in 200 ml. of refined kerosene. Thenormal cupric salts prepared as in Example '11 formed a viscous masswith the oil, but the addition of nicotine resulted in formation of thecopper-nicotine compounds in complete solution. Parallel experiments inwhich different grades of hydrocarbon oils were substituted for thekerosene yielded similar results in all respects.

Example X One-tenth average molar weight of the mixed cocoanut oil fattyacids (20.0 grams) was neu-. tralized with the theoretical quantity ofstandard sodium hydroxide solution and then precipitated by addition ofthe theoretical amount of standard cupric acetate solution. The correctamount of nicotine and 200 ml. of kerosene was added and shakenvigorously. On standing, a clear, green solution of the mixedcoppernicotine compounds in the oil resulted.

Example XI One-tenth molar weight of commercial oleic acid (28.4 grams)was neutralized with the theoretical amount of sodium hydroxide solutionand 200 m1. of kerosene was added. The equivforming acid, said acidbeing selected rrom the group consisting of the saturated aliphaticmonocarboxylic acids having from 6 to 14 carbon atoms. inclusive, theunsaturated aliphatic monocarboxylic acids having from 6 to 18 carbonatoms, inclusive, abietic acid, and a mixture of them, by mixing thenicotine and normal cupric salt together in the proportion of not morethan 1 /2 molecules of nicotine for each molecule of the cupric salt.

2. A- process for thepreparation or oil-soluble copper-nicotinecompounds comprising reacting nicotine with a normal cupricsalt ofabietic acid by mixing the nicotine and normal cupric salt together. inthe proportion ofthan 1% molecules of nicotine for each moleculeof thecupric salt.

3. A process for the preparation oi oil-soluble I copper-nicotinecompounds comprising reacting alent amount of cupric acetate solutionwas then added slowly while agitating the mixture. After standing forseveral hours or longer, the oil layer containing the cupric oleate insolution separated from the water layer containing the impurities insuspension. The addition of 8.1

'grams of nicotine produced the required chemiwherein R is a monovaientsaturated aliphatic radical having from 5 to. 13 carbon atoms,inclusive, a monovaient unsaturated aliphatic radnicotine witha normalcupric salt of a saturated aliphatic monocarboxylic acid having-from 6to 14 carbon atoms, inclusive, by mixing the nicotine and normal cupricsalt together in the proportion of not more than 1 /2 molecules ofnicotine foreach molecule of the cupric salt.

4. A process for the preparation of oil-soluble copper-nicotinecompounds comprising reacting-- nicotine with a normal cupric salt of an-unsaturated aliphatic monocarboxylic--acidhaving from 6 to 18 carbonatoms, inclusive, by mixing the nicotine and normal cupric salt togetherin the proportion of not more than 1% molecules ofnicotine for eachmolecule of the cupric salt.

5. A process for the preparation of oil-soluble copper-nicotinecompounds comprising reacting nicotine with mixed cupric salts of mixedcocoanut oil acids by mixing the nicotine and cupric salts together inthe proportion of not more than 1 molecules of nicotine for eachmolecule 01' the cupric salts.

6. A process of preparing a petroleum hydrocarbon oil solution ofcoppernicotine compounds comprising dissolving in the hydrocarbon oil asoap-forming acid, said acid being selected from the group consisting ofthe saturated aliphatic monocarboxylic acids having from 6 to 14 carbonatoms, inclusive, the unsaturated aliphatic monocarboxylic acids havingfrom 6 to 18 carbon atoms, inclusive, abietic acid, and a mixture orthem. forming a normal cupric salt of the soap-- forming acidJoyftreatingthesolutionwith an 1 aqueous cupric .salt, and .mixingnicotine therewith in the proportion or substantially one molescgle oinicotine tor each'molecuie or the cupric I. A process of preparing apetroleum hydrocarbon oll solution ofa copper-nicotine compoundcomprising mixing a soap-forming acid, said acid being selected from thegroup consisting of the saturated aliphatic monocarboxylic acids havingfrom 6 to 19mm atomsr'inciugive, the unsaturated aliphaticmonocarboxylic acids having from 6 to sive, abietic acid, and a mixtureof them, an aqueous cupric salt, and nicotine with the petrolumhydrocarbon oil in the proportion of substantially one molecule ofnicotine -for each molecule of the cupric salt. 1

8. A process of preparing a copper-nicotine compound comprising mixing asoap-forming acid, said acid being selected from the group consisting ofthe saturated aliphatic monocarboxylic acids having from 8 to 14 carbonatoms, inclusive, the unsaturated aliphatic monocarboxylic acids havingfrom- 6 to 18 carbon atoms, inclusive, abietic acid. and a mixture ofthem, an

aqueous solution of the cuprlc salt, and nicotine with a volatilesolvent, in the proportion of substantially one molecule of nicotine foreach molecule oi the cupric salt, followed by evaporation of thesolvent.

9. A composition or matter represented by the formula (RCOO)2CILC10H14N2 where R. is selected from the group consisting of amonovalent saturated aliphatic radical containing from 6 to 13 carbonatoms, inclusive, a mono- 18 carbon atoms, inclu-' auger:

valent ;.unsaturated aliphatic radical containing from 5 to 17 carbonatoms, inclusive, the abietyl radical, and a, mixture of them, andwherein CmHuNa represents a molecule 01' nicotine.

10. A composition of matter represented by the formula R-cooncuomm41owhere R is a monovalent saturated aliphatic radical containing from 5 to18 carbon atoms,

inclusive, and wherein CroHuNz' represents a molecule of nicotine.

11. A composition of matter represented by the formula (R-COO)2ClLC1oH14Na (RCOO) 2CILCioHi4N2 I of matter represented by the where Ris an abietyl radical, and wherein molecule of nicotine.

C1oHi4N2 represents a CLAUDE R. SMITH.

to 17 carbon atoms, in-.

